Welding and cutting torch



C. R. RICHTER WELDING AND CUTTING TORCH July 14, 195 3 2 Sheets-Sheet 1.

Filed NOV. 23, 1948 w 1 a K In vent or" Char/e f3, R/cht er July 14, 1953 c. R. RICHTER WELDING AND CUTTING TORCH 2 Sheets-Sheet 2 Filed Nov. 23, 1948 1 2 x I ll/l 0 w H 9 a F Patented July 14, 1953 UNITED "STATES PATENT OFFICE Charles R. Richter, Schenectady, N. Y.

Application November 23, 1948, Serial No. 61,719

. 1 Claim. 1

welding, brazing, cutting, and the like operations and particularly to a torch of this charac ter which, although it may be used with combustible gases under high pressure, is primarily designed for use with gases under low pressure, such as gases used in cities for cooking and other purposes.

So far as I am aware, there is no torch available at the present time which can be used satisfactorily for welding with gas, such as city gas, under comparatively low pressure. There are torches in which such gases under comparatively high pressure can be used for welding, but expensive extra equipment, in the way of compressers, storage tanks and the like, is required.

As is well understood in the art, in order to produce the high temperatures which are necessary for welding, large volumes of gas must be burned in a restricted zone at a 'very high rate of combustion The principal difficulty encountered in attempting to use gases, and particularly gases such as city gas having a low B. t. u. rating, directly from the mains or pipes under the pressures universally prevailing therein, is to discharge the gas from the nozzle of the torch at a rate sufficiently high to develop the necessary heat. There is no particular problem involved where combustible gas is available from a high pressure source of supply but the situation is quite different where the gas is delivered to the torch from a low pressure supply thereof.

One of the principal objects of my invention is to provide a torch which may be successfully used for welding, brazing, cutting, heating and the like with gas drawn directly from a low pressure supply thereof. Another object is to provide a single torch unit which may be converted from a welding torch to a cutting torch, and vice versa, by merely changing the nozzle thereof. A further object is to-provide a torch of such design that a combustible gas may be delivered thereto directly from a low pressure source of supply but which will be delivered to and discharged from the nozzle of the torch at a substantially higher pressure than exists in the source of supply and thoroughly admixed with oxygen.

I accomplish these and other objects which will be apparent as the description of my invention proceeds, by means of the novel elements and the combinations and arrangements thereof described below and illustrated in the accompanying drawings in which- 1 is a side elevation view portions broken away and portions in section showing my torch with a welding nozzle thereon;

Fig. 2 is a longitudinal section through the t p;

Fig. 3 is a small scale view partially in section of the tip when equipped with a cutting nozzle;

Fig. 4 is a section of Fig. 2 in the plane 4-4;

Fig. 5 is an enlarged side elevation with portions broken away of the valve housing shown at the bottom of Fig. 1;

Fig. 6 is a section of Fig. 5 in the broken planes 6-6;

Fig. 7 is a section of Fig. 5 in the broken planes 'I-l;

Fig. 8 is an enlarged side elevation of the valve housing at the other end of the handle and to which the torch pipe is attached; Fig. 9 is an enlarged, longitudinal sectio through the injector;

Fig. 10 is a section of Fig. 9 in the plane lll-l 0;

Fig. 11 is asection of Fig. 8 in the plane |l--l I;

and i 'Fig. 12 is a section of Fig. 8 in the broken planes l2--I2.

Referring to the drawing and first, more particularly to Figs. 1, 2, 3 and 4, my torch comprises a torch pipe I, of comparatively, large cross-sectional area throughout the major portion thereof and which is secured to the valve housing 2 by means of the coupling nut 3. Secured to the free end of the torch pipe I is the tip shown in Figs. 2 and 3, represented. generally by the numeral 4. The tips shown in Figs. 1, 2 and 3 are identical except that the tip nozzle 5, shown in Fig. 3, is a cutting nozzle whilethe tip nozzle 6, shown in Figs. 1 and 2, is a welding nozzle.

Each of the tips comprises a cup-like base I, which is permanently secured to the torch pipe I, and which is open at the other end and internally threaded, as shown at 8, to receive the interchangeable nozzles 5 and 6. The base I has an internally threaded diaphragm or spider 9 therein which is provided with a plurality of circumferentially-spaced, longitudinally-extending passages ID to passthe gas from the torch pipe I. Threaded into the spider 9 and disposed in laterally-spaced relation to the interior wall of the base I, to provide for the flow of gas therebetween, is a small tubeor pipe ll having the passage l2 through the forward portion thereof substantially reduced in size to discharge a needle-like jet of oxygen for use in cutting. The

tube or pipe II is counterbored at the rear end to receive the small pipe 13, the function of which will be described below. The forward end of the tube II is provided with a cylindrical enlargement l4. having a plurality of equicircumferentially-spaced passages l therethrough for the flow of gas. When the torch is to be used for welding, a nozzle of the type shown at 6 in Figs. 1 and 2, is threaded into the base i and is provided at its forward extremity with a comparatively small discharge orifice or passage 3. The cylindrical enlargement [4 on the-pipe H is of less diameter than the internal diameter of that portion of the nozzle 6 immediately surrounding it so that an annular gas passage it is provided therebetween. The passage through the nozzle 6 beyond the enlargement H; on the pipe I! converges towards the discharge orifice It, as shown at l8.

Referring now more particularly to Figs. l, 8, 9, 10, 11 and 12, the torch pipe I, adjacent its con nection to the valve housing 2, is provided with means |9 forming a Venturi-like restriction therein and the valve j housing 2 has threaded therein,

' as shown at 20 in Fig. 11, a nozzle element 2| of a second valve housing 43 with which the pipes 33, 31 and 39 communicate. The pipe 33 communicates with a passage 44 in valve housing 43 which, in turn, communicates with the threaded nipple 45 to which a pipe leading to a source of supply of oxygen under pressure is adapted to be connected. It will be apparent from the foreneedle valve 46 with a space 41 in the housing 43 which, in turn, communicates with pipe 3?.

- ThllS, by opening the valve 46, oxygen from the having a comparatively small passage 22 therethrough and which is tapered at the free end thereof, as shown at 23. The nozzle2| is sodisposed with respect to the means l9 forming the Venturi-like restriction in the torch pipe I, and in such axially and laterally spaced relation thereto.

that it will cooperate with-the means |9to form an injector, the function of which will be described below. Extending from the valve housing 2 through the means forming the restriction in the torch pipe I, and running longitudinally through the torch pipe I, is the small pipe or tube l3 which communicates with the pipe or tube H in the tip.

Referring now more particularly to Fig. 12, the valve housing 2 is provided with a poppet valve 24 which is normally held against its seat 25 by means of the helical spring 26 and the threaded plug 21. A plunger 28 cooperates with the valve 24 and maybe depressed to open .the valve by squeezing the lever 29, which is pivotally mounted at 30, between the ears 3| on.the valve housing 2.

The pipe |3 communicates with a space 32 on the plunger side of the valve 24 and a pipe 33 communicates with the space 34 in the valve housing 2 on the other side of the valve 24. Thus, communication between the pipe 3 and the pipe 33 is normally cut off by the valve 24 but communication may be provided between these pipes by opening the valve 24 by manipulating the lever 29.

The valve housing 2 is provided with separate passages 35 and. 36 therethrough (see Fig. 11) in addition to the passages through the valve 24. The passage 35 communicates with the nozzle 2| and a pipe 31 which is secured in the lower end of the valve housing 2 is adapted to supply oxygen to the nozzle 2|. The passage 36 communicates directly with the torch pipe through the annular passage 38 in the valve housing which surrounds nozzle 2|, and a pipe 35 which is secured to the bottom of the valve housing 2 is'adapted to supply a combustible gas through the passages 35 and 38 to the zone 43 in the torch pipe I (see Figs. 1 and 9) which immediately surrounds the discharge end of the nozzle 2|. Enclosing the pipes 33,3! and 39 is an elongated, cylindrical casing 4| which is soldered or otherwise secured at 42 by means (not shown) to the bottom of the valve housing 2, as shown in Figs. 8 and 11. 7

Referring now more particularly to Figs. 5, 6 and 7, the other end of'the casing 4| is secured by soldering or otherwise (not shown) 120t top source of supply thereof may flow through the nipple 45, passage 44, through the valve 46 and pipe 3'! directly to the nozzle 2| (see also Fig. 11). Hence, by opening valve 46, oxygen under high pressure from the source of supply thereof will be discharged through nozzle 2| into the Venturilike restriction in torch pipe I.

Pipe 39, which communicates directly with the torch pipe in the zone thereof surrounding the nozzle 2|, communicates with a space 43 (see Fig. 6) in valve housing 43 and with the space 48 may placed into communication with, or cut ofi from, communication with the passage 49 in the housing 43 by means of the valve 5!]. The passage 49 communicates with nipple 5| which is adapted to be connected to a source of supply of a combustible gas such, for example, as a city gas main.

By opening valve 50, such gas may flowireely through pipe 39 into the space in the torch pipe around nozzle 2|. In operation, the nipples 45 and 5| are connected, respectively, to a source of supply of oxygen under substantial pressure and a source of gas supply which may be under very low pressure. If the torch is to be used for welding, the nozzle 6 is used on the tip and the valves '46 and 50 are opened and adjusted to produce,

when ignited at the orifice H5 in the nozzle 6, a flame'of the desired character. The oxygen issuing at substantial velocity from the nozzle 2| through the restriction in the torch pipe, induces a flow of the low pressure combustible gas surrounding the torch 2|, through the restriction in torch pipe I into said pipe where it is thoroughly intermixed with the oxygen and flows from said pipe through the passages If), the space surrounding the pipe ll within the nozzle 6, around the" cylindrical enlargement on the end of pipe I and through the passages |5 therein into the space 52 in the forward end of the nozzle 6, and thence through the discharge passage IS in the end of said nozzle. 7

When the torch is to be used for cutting, it is necessary only to unscrew the nozzle 6 from the base of the tip and substitute therefor the nozzle 5, as shown in Fig. 3. The nozzle 5'has, at its outer end, an inturned lip 53 which overlies the forward marginal edge of the enlarged cylindrical portion M on pipe ll, so that the flow of gas therethrough is confined to the passages 5. Gas flowing through these passages serves to heat and maintain hot the material to be cut andthe cutting is accomplished by pressing lever 29 to open valve 24 which discharges a jet of oxygen from the passage |2 in the center of-the cylindrical enlargement |4.

From the foregoing it will be apparent that my torch may be readily convertedfrom a welding t h to a cutting torch and vice versa, bymerely changing the nozzles 5 and 6, as the case may be. Although the combustible gas which is delivered to the space 40 in the torch pipe around the nozzle 2| may be at very low pressure, the injector functions not only to induce a flow of this low pressure gas into the torch pipe and intermix it there with the oxygen, but also to build up a much higher pressure on the mixture between the nozzle 6 and the restriction when th torch is used for welding.

When used for cutting-the mixture of gas and oxygen discharged through the passages 15 around the end of the pipe ll, serves to heat and maintain hot the work to be out by the jet of oxygen issuing from the passage 12.

Instead of straight oxygen, my torch may be used with ordinary air under suitable pressure as a source of supply of oxygen. But, since the oxygen content of air is only about one-fifth of the total volume thereof, the air ,must be delivered to the nozzle at a rate of approximately five times as fast as oxygen in order to supply the same volume of oxygen per unit of time. Thus, with the same pressure on the sources of supply, if air is used instead of oxygen, the air passages through the torch must be substantially enlarged. In any case, however, where the torch is to be used with gas from a low pressure source of supply, it is very important that the gas passages leading from said source to the zone around the injector nozzle be of substantial size for the free flow of gas therethrough. It i equally important that back pressure on the venturi be reduced to a minimum by making the restricted portion of the passage therethrough comparatively short, and rapidly increasing the crosssectional area of the passage beyond the dischar e end of said restriction. Likewise, it is important to provide a passageway of comparatively large cross-sectional area between the venturi and the nozzle. Otherwise, the torch will not function with gas, such as gas from a city main which it is primarily designed to use, and which is ordinarily under a pressure of substantially less than one pound per square inch.

While I have described my invention in its preferred embodiment, it is to be understood that words which I have used are words of description rather than of limitation and that changes, within the purview of the appended claim, may be made without departing from the true scope and spirit of my invention in its broader aspects.

What I claim is:

A combined welding and cutting torch adapted for use with a combustible gas drawn directly from a source of supply thereof, such as a city gas main, under low pressure of the order of less than one pound per square inch; said torch comprising a torch pipe; a tip secured to the end of said pipe and having a comparatively small centrally-disposed discharge opening therein and a 6 plurality of comparatively large openings around said central opening; said larger openings communicating with said pipe; passage-forming means communicating with said pipe adapted to conduct said gas from said source of supply thereof to said pipe and forming with said pipe a substantially straight passage of substantial cross-sectional area throughout the major portion of the length thereof, whereby to provide for the free flow therethrough of said gas under said low pressure; means forming a comparatively short, venturi-like restriction in said passage; a nozzle centrally disposed in said passage in a zone relatively remote from said tip to provide for the free flow of said gas therearound and cooperating with said restriction to form an injector; means communicating with said nozzle for conducting oxygen thereto from a source of supply thereof under comparatively high pressure; whereby the discharge oxygen from said nozzle will induce a flow of said gas from the zone around said nozzle through said restriction; the crosssectional area of said passage increasing rapidly from the discharge side of said restriction to reduce back pressure on the gas flowing through said restriction; means for conducting oxygen directly from said source of supply thereof to said centrally-disposed discharge opening in said tip, and a valve having an actuating lever adapted to be manipulated by an operator for controlling the flow of oxygen through said last mentioned means; said tip having a threaded portion adapted to cooperate with interchangeable nozzles for converting said torch from a welding to a cutting torch and vice versa.

CHARLES R. RICHTER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,114,706 Brousseau Oct. 20, 1914 1,216,875 Stettner Feb. 20, 1917 1,246,573 Fausek et a1 Nov. 13, 1917 1,259,885 McGee Mar. 19, 1918 1,266,858 Reyburn May 21, 1918 1,274,052 Jenkins July 30, 1918 1,316,681 Burritt Sept. 23, 1919 1,361,667 Baudet Dec. 7, 1920 1,424,189 Strobot Aug. 1, 1922 1,660,328 Fausek et al Feb. 28, 1928 1,662,520 Jenkins Mar. 113, 1928 1,809,652 7 Vincent June 9, 1931 1,832,623 Fausek et al. Nov. 17, 1931 2,238,470 Jacobsson et al Apr. 15, 1941 2,346,774 Anthes May 16, 1944 FOREIGN PATENTS Number Country Date France Sept. 3, 1923' 

